Cisco IOS stable/production safe versions?

Daniel Corbe corbe at
Wed Jan 28 14:15:58 UTC 2015

Nick Ellermann <nellermann at> writes:

> I have a Cisco IOS specific question for the group and also
> specifically related to the 6500 platform. We have always been very
> conservative with our IOS version that we run in production, we are
> still running a pretty old safe harbor build of 12.2.x on SUP 720
> 3BXLs with BGP and OSFP routing. Any advice from fellow network
> operators that are running the 6500 platform in the core still for
> versions that are considered safe for production? We are stable, but I
> am really wanting access to features such as Netflow v9, etc.
> Thanks for any advice!

You're pretty spot on with your thinking here.  Don't upgrade unless
there's a known vulnerability, a bug fix or a feature that you need on a
particular device; and don't expose your management to the Internet.

tl;dr: don't fix what isn't broken.

Having said that; make use of the software download tools on your CCO
account.   Cisco has a list of recommended builds for your particular
platform and code train.

When in doubt you can always fall back to S-train stuff on a Sup720.
-S images were made for service providers and are generally very stable.


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